I have lowered the float and the water will stop. But within a few hours the tank will fill again to the point of leaking. What can I try next?

I have lowered the float and the water will stop. but within a few hours the tank will fill again to the point of leaking. What can I try next?
Replace the ballcock. Good luck, Tom

Yep, Tom nailed it. Your current ballcock is failing to totally seal once the float tells it to stop. Most are not worth fixing with good replacements available for $10. I think most all of us would say buy a Fluidmaster 400 A and be done with it, You can also get it in a kit to replace everything inside tha tank while you are in there.

Both Tom and Bob have given you a good advice, here is a picture of the fluidmaster fill valve, good luck.

John

Another important point here is that the overflow pipe (see picture below) needs to be cut down so the next time this happens water will flow down the oveflow pipe and not out the handle! The plumber that installed the overflow tube/flush valve assembly should have cut this tube down to the right height.

Here, take a hacksaw blade and cut the overflow pipe so it is about an inch BELOW the hole in tank for toilet handle. Be careful and hold the tube tight and cut slowly.

This way there can never be an overflow condition out the handle and onto floor... ;)

Good luck...

MARK

Also, lower the height of the overflow pipe...

Milo, I think that's what Mark just said.

Ooooops, of course... Mark covered it all...